Crates / downcast / Alternatives
Rust crate alternatives · data Oct 24, 2026
Alternatives to downcast
Short answerThe closest alternatives to downcast on crates.io data are thiserror (5M real downloads a day), itertools (4.5M real downloads a day), once_cell (3.8M real downloads a day). Of the 8 we list, the most used is thiserror, and 7 shipped a release in the last year. downcast itself gets 335,698 a day with 19 dependents.
Every alternative we found
| Alternative | Real downloads a day | vs downcast | Dependents | Last release | Why it is listed | |
|---|---|---|---|---|---|---|
| thiserror Foundational | 5,048,791 | 15.04x | 75,923 | 31d | category No standard library, category Rust patterns | compare |
| itertools Widely used | 4,545,996 | 13.54x | 8,656 | 4mo | category No standard library, category Rust patterns | compare |
| once_cell Widely used | 3,785,180 | 11.28x | 8,656 | 7mo | category Rust patterns | compare |
| pin-project-lite Widely used | 3,270,978 | 9.74x | 1,708 | 8mo | category No standard library, category Rust patterns | compare |
| zerocopy Established | 3,245,504 | 9.67x | 878 | 11d | category Rust patterns | compare |
| anyhow Foundational | 2,875,638 | 8.57x | 52,113 | 3mo | category No standard library, category Rust patterns | compare |
| scopeguard Established | 2,724,718 | 8.12x | 567 | 3.3y | category No standard library, category Rust patterns | compare |
| zerovec-derive Pulled in | 2,561,390 | 7.63x | 6 | 2d | category No standard library, category Rust patterns | compare |
How to choose
- Same job, not the same API. Each line is listed because it shares a crates.io category or keyword with downcast; read its description before you swap.
- More dependents means more answered questions and a smaller chance it disappears.
- Check the last release against how fast you need fixes. For downcast: is it still maintained?
Rules
Alternatives = tracked crates (top 1000 by downloads) that share a specific crates.io category (2 points each) or keyword (3 points each) with downcast, most similar first; its own parts (same name prefix) and crates it depends on or that depend on it are left out, because those are companions, not substitutes. Real downloads = quiet-day median, crates.io data Oct 24, 2026. Built when we find 3 or more.
Up next
The closest alternative: Foundational and steady. 5,048,791 real downloads a day.thiserrorRust crate. derive(Error). Real use: 5M downloads a day on quiet days; 75,923 crates depend on it.Read it next →Also worth your time